Containers in the Data Center
Learn about containers, the difference between containers and virtual machines, and important things to remember while designing applications for containers.
What are containers?
Containers have invaded the data center, pushed there by developer insistence. Containers promise to deliver the process isolation and packaging of a virtual machine together with a developer-friendly build process. The container hypothesis says, “I’ll never again have to ask if production matches QA.”
Are containers VM?
Containers in the data center act a lot like virtual machines in the cloud (see Virtual Machines in the Cloud). Any individual container only has a short-lived identity. As a result, it should not be configured on a per-instance basis. This can cause interesting effects with older monitoring systems that need to be reconfigured and bounced every time a machine is added or removed.
A container won’t have much if any, local storage, so the application must rely on external storage for files, data, and maybe even cache.
The challenge with containers
The most challenging part of running containers in the data center is definitely the network. By default, a container doesn’t expose any of its ports (on its own virtual interface) on the host machine. We can selectively forward ...